           (GL11/glViewport 0 0 framebuffer-width framebuffer-height)
           (GL11/glClearColor 0.0 1.0 0.0 1.0)
           (GL11/glClear (bit-or GL11/GL_COLOR_BUFFER_BIT GL11/GL_DEPTH_BUFFER_BIT))
+          (GL11/glBlendFunc GL11/GL_ONE GL11/GL_ONE_MINUS_SRC_ALPHA)
           (GL20/glUseProgram fb-program-id)
           (GL20/glUniformMatrix4fv u-fb-PMatrix false (ortho-matrix-buffer framebuffer-width framebuffer-height p-matrix-buffer))
           (except-gl-errors (str "u-fb-PMatrix - glUniformMatrix4  " u-fb-PMatrix))

     :texture-coords-vbo-id texture-coords-vbo-id
     :texture-coords-count texture-coords-count
     :vao-id vao-id}))

;; Normally this would be a record, but until http://dev.clojure.org/jira/browse/CLJ-1224 is fixed
;; it is not performant to memoize records because hashCode values are not cached and are recalculated

    (org.lwjgl BufferUtils)
    (java.nio FloatBuffer ByteBuffer)
    (java.nio.charset Charset)
    (org.lwjgl.opengl GL GLUtil GL11 GL12 GL13 GL14 GL15 GL20 GL30 GL32)
    (org.lwjgl.glfw GLFW GLFWVidMode GLFWErrorCallback GLFWCharCallback GLFWKeyCallback GLFWMouseButtonCallback GLFWCursorPosCallback)
    (org.lwjgl.system Platform)
    (org.joml Matrix4f Vector3f)
